Encapsulated magnetic proximity switch

ABSTRACT

A magnetically actuated electrical switch, the movable parts of which are encapsulated within a molded housing, with such parts comprising a pair of terminal members, one of which provides a stationary contact head normally spaced from a movable switch blade carried by the other terminal member, with the latter terminal member providing a pivotal connection for one end of a magnetically attracted switch blade bridging member that has its opposite end connected to the free and movable end of the switch blade.

United States Patent [191 Habecker 1 Jan. 16, 1973 ENCAPSULATED MAGNETIC 3,238,325 3/1966 Scata ..335/l54 PROXIMITY SWITCH 3,236,965 2/l966 Bianco et al ..335/l88 [75] Inventor: John W. Habecker, Waukegan, Ill. Primary Examiner Hamld Brooms [73] Assignee: Cherry Electrical Products Corporaytion, Waukegan, Ill.

57 ABSTRACT [22] Filed: Aug. 20, 1971 1 A magnetically actuated electrical switch, the movable N05 "3567 parts of which are encapsulated within a molded housing, with such parts comprising a pair of terminal 52 11.5. CI ..335/l88 members, which PM!es a statimary 51] Int. Cl. ..H0lh 5/02 head (many Spaced 3 mvablwwitch blade [58] Field of Search 335/188 151 154 202 205 carried by the other terminal member, with the latter terminal member providing a pivotal connection for one end of a magnetically attracted switch blade [56] References cued bridging member that has its opposite end connected UNITED S T PATENTS to the free and movable end of the switch blade.

2,568,476 9/1951 Weirich et al ..335/l88 1 Claim, 7 Drawing Figures w a? 1'1 AZ f we! Nit Q \\\\2\ i ENCAPSULATED MAGNETIC PROXIMITY SWITCH SUMMARY OF THE INVENTION An encapsulated proximity switch actuated by a remote magnet, with the switch providing a contact mechanism actuated by an armature-like member caused to be moved by the proximity of a magnetic field generated externally of the encapsulated switch, a pair of terminal elements having terminal connecting ends protruding out of the sealed switch housing, with one of the elements providing a stationary contact head within the housing and within the path of movement of a complementary contact carried by a movable switch blade. The switch blade has one end fixedly attached to the other terminal element and its opposite end connected to the corresponding end of a pivotal actuator. The actuator is made from ferrous material and is so formed as to present in close proximity to one inner wall surface of the housing an enlarged area that is readily attractable to a remote magnetic field generated exteriorly of the switch housing and which, when so attracted, will move such switch blade into contact with said one terminalelement.

GENERAL DESCRIPTION For a proper understanding of the concepts of the present invention, reference is made to the accompanying drawing illustrating the preferred embodiment and structural characteristics of this invention, and in which:

FIG. 1 is a perspective view of the encapsulated switch;

FIG. 2 is a plan view of one of the housing sections of the switch;

FIG. 3 is a plan view of a corresponding housing section, with the switch components contained within its cavity;

FIG. 4 is a detailed sectional view of the switch in an unactuated position;

FIG. 5 is a detailed sectional view similar to FIG. 4, showing the switch in an actuated position;

FIG. 6 is an end sectional detail view of the switch;

FIG. 7 is a perspective view of the components of the switch in exploded relationship.

Encapsulated in a single-cavity, two-piece housing 10 preferably molded from thermo-plastic material capable of being ultrasonically welded together into a sealed unit, are the components of the switching mechanism of this invention.

As shown, one piece 11 of the housing 10 provides extensions 12 laterally extending from the short sides of the generally rectangularly shaped piece. These extensions 12 may be utilized to provide mounting holes 13 by which the switch may be conveniently connected to a suitable supporting unit.

The piece 11 is provided with an interior cavity 14 and has its two parallel longitudinal edges 15 and 16 notched as at 17, 18, 19 and 20, as shown in FIG. 2. The complementary piece 21 is formed to provide a related cavity 22. However, one end of this cavity 22 is partially restricted by a block 23 that provides a shoulder 24 which extends inwardly from one end of the cavity 22, the purpose of which will be hereinafter made apparent.

A terminal member 25 is provided and it comprises an elongated tail portion 26 and an enlarged head portion 27. The tail portion 26 is adapted to lie within the confines of the notch 17 formed in the longitudinal edge 15 of the housing piece 11. The enlarged head portion 27 of the terminal 25 will have a corresponding edge portion positioned'within the notch 18 formed in the longitudinal edge 16 ofthe housing piece 11.

Connected to the terminal 25 and extending laterally at right angles thereto, is a switch blade 28 (FIG. 7) that is normally deflected concave throughout its longitudinal plane after installation (see FIG. 4). One end of the blade 28 provides a lateral tongue 29 that is adapted to be projected through a slot 30 formed in the enlarged head portion 27 of the terminal 25, with that end of the blade 28 fixedly attached in any suitable manner to the underside of the terminal 25, as shown.

A second terminal 31 provides an elongated tail section 32 which is cohnected by a lateral flange 33 to a rectangularly shaped head portion 34, the short longitudinal edge of which is provided with a depending flange 35 that in turn supports a shoulder 36 which extends longitudinally in the normal plane of the tail section 32. By this construction, the rectangularly shaped headportion 34 is disposed in a raised position with respect to the tail portion 32 and shoulder 36 of the terminal 31.

The terminal 31 has its tail section 32 adapted to be positioned in the notch 19 formed in the longitudinal edge 15 of the housing piece 11, and its shoulder 36 seated within the notch 20 formed in the longitudinal edge 16 of the housing piece 11, as shown in FIG. 6. In such position the raised head portion 34 of the terminal 31 will be in spaced relation with respect to the switch blade 28. The switch blade 28 and the head portion 34 of the terminal 31 each provide contact heads 37 and 38, respectively, which, when the switch is actuated, provide electrical contact between the blade 28 and the terminal 31.

An actuator 39, which is generally U-shaped so as to provide a substantially rectangular medial surface area 40 and depending arms 41 and 42, is associated with the switch blade 28 for action thereof. The actuator 39 is preferably formed from ferrous material so as to be movably responsive to a magnetic field moved into proximity therewith.

The arm 41 of the actuator 39 provides a curved tab 43 which is adapted to be projected through a slot 44 formed in the enlarged head portion 27 of the terminal 25, with the slot 44 in longitudinal alignment with the normal plane of the switch blade 28. The opposite arm 42 of the actuator 39 is formed so as to be of a width less than the medial area 40 of the actuator 39 and has its opposite edges notches as at 45 so as to receive therein the split end portions 46 of the blade 28. When the heretofore described parts are in their assembled relation within the housing 10, they will assume the positions shown in FIGS. 4 and 6. By the inherent character of the switch blade 28, the actuator 39 will be in the position shown in FIG. 4, with the end surface 47 of the arm 42 seated upon the shoulder 24 provided by the block 23 of the housing piece 21.

In such position the contact heads 37 and 38 of the switch blade 28 and terminal 31 are spaced from each other and are in an open switch position. When a so as to raise the arm 42 thereof as well as the free end of the blade 28 connected thereto, into the position shown in FIG. 5, wherein the contact heads 37 and 38 will be closed and an electrical circuit completed therethrough.

From the foregoing, it is apparent there is provided an encapsulated magnetic proximity switch which has relatively few parts, certain of which have simple movable connection therebetween, yet which is extremely reliable in operation and economical in manufacture.

While 1 have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. An electrical switch adapted to be actuated by the proximity of amagnetic field generated externally of the switch, comprising a. an encapsulated cavitied housing,

b. a pair of parallel terminal members fixedly carried by said housing and extending coplanar with respect to each other,

c. an elongated switch blade supported on one end of one of said terminal members and extending transversely and in the normal plane thereof,

. the other of said terminal members providing a medial bridge portion disposed above and transversely of said switch blade,

e. and a magnetically attractable substantially U- shaped switch actuator having one arm pivotally mounted on said one of said terminal members and extending in spaced parallel relation to said switch blade and over and beyond said bridge portion of said other terminal'member with its opposite arm connected to the free end of said switch blade to move the same into contact with said bridge portion of said other terminal member when said actuator is in proximity to a magnetic field generated externally of said housing. 

1. An electrical switch adapted to be actuated by the proximity of a magnetic field generated externally of the switch, comprising a. an encapsulated cavitied housing, b. a pair of parallel terminal members fixedly carried by said housing and extending coplanar with respect to each other, c. an elongated switch blade supported on one end of one of said terminal members and extending transversely and in the normal plane thereof, d. the other of said terminal members providing a medial bridge portion disposed above and transversely of said switch blade, e. and a magnetically attractable substantially U-shaped switch actuator having one arm pivotally mounted on said one of said terminal members and extending in spaced parallel relation to said switch blade and over and beyond said bridge portion of said other terminal member with its opposite arm connected to the free end of said switch blade to move the same into contact with said bridge portion of said other terminal member when said actuator is in proximity to a magnetic field generated externally of said housing. 